一个含苯甲酸配体的Mn-Ce混合金属簇合物的合成、晶体结构与磁性研究

本文使用(NH4)2Ce(NO3)6氧化Mn2+法合成了1个结构新颖的Mn-Ce混合金属簇合物[Mn3Ce2(O)5(O2CPh)9(CH3OH)3]·2CH3CN(1.2CH3CN,HO2CPh代表苯甲酸),并对其进行元素分析、红外光谱、单晶X-射线结构分析、磁性等表征。结构分析表明,化合物1.2CH3CN属于三斜晶系P1空间群,结构中2个Mn4+离子、2个Ce4+离子和4个桥连μ3-O原子组成1个不规则的立方烷,然后通过另1个桥连μ3-O原子与另1个Mn3+离子相连。晶胞内分子间没有氢键作用,但存在较强的π-π堆积作用。磁性研究表明,簇合物内Mn离子之间存在铁磁性耦合作用,基态自旋值S=5和磁各向异性参数D=-0.31 cm-1,交流磁化率没有频率依赖现象。     

四吡唑取代的[Mn8Ce]簇合物的合成、晶体结构与磁构关系研究

向Mn（O₂CCH₃）₂·4H₂O、吡唑和醋酸的乙腈/甲醇溶液中加入（NH₄）₂Ce（NO₃）₆首次得到1个四吡唑取代的[Mn₈Ce]混金属簇合物[Mn₈O₈Ce（O₂CCH₃）₁₂（pyr）₄]·2CH₃OH（2·2CH₃OH,pyr为吡唑配体）,并对其进行单晶结构分析、红外、元素分析和磁性研究。单晶结构研究表明,该化合物属于单斜晶系,P2₁/c空间群,8个Mn原子形成1个不在同一平面的八元环,然后通过8个μ₃-O^2-与位于环中心的1个Ce^Ⅳ连接起来。磁性研究表明,化合物中Mn³⁺离子之间是弱的铁磁性作用,基态自旋值S=6,交流磁化率虚部仅显示较微弱的频率依赖现象。通过研究系列[Mn₈Ce]簇合物的磁构关系发现,配合物中随着含孤立μ₃-O^2-的∠MnOMn键角的增大和随着含桥连羧基O的∠MnOMn键角的减小,Mn³⁺间的铁磁性耦合增强,并进而导致化合物基态自旋值S的增大。     

含混合多齿螯合配体双缺口立方烷型四核Mn配合物的合成、晶体结构与磁性研究

本文报道了一个含混合多齿螯合配体的四核Mn配合物Na2[MnIII2MnII2(pdmH)2(L)2(N3)2]·2CH3OH·2H2O(1·2CH3OH·2H2O,pdmH2为2,6-吡啶二甲醇,H2L为2,6-吡啶二甲醇与2,2-二吡啶酮水合物的脱水物),并对其进行单晶结构分析、红外、元素分析和磁性研究。单晶结构分析表明,该化合物属于三斜晶系P1空间群,分子中2个Mn2+、2个Mn3+及6个来自pdmH-或L2-配体的O原子构成1个双缺口立方烷结构。磁性研究表明Mn2+与Mn3+之间为弱的反铁磁性耦合作用(J1=-0.89 cm-1,J2=-1.13 cm-1),Mn3+离子之间为稍强的铁磁性耦合作用(J3=3.20 cm-1),基态自旋值S=2,交流磁化率研究表明,在所测试条件下,其虚部没有表现出单分子磁体所具有的频率依赖现象。     

含三乙醇胺及硫氰酸根的混价七核锰配合物{K[MnⅡMn6Ⅲ(teaH)3(tea)3(NCS)6]}n的合成、结构和磁性研究

采用MnCl2(或Mn(NO3)2)与teaH3和KSCN混合配体合成了1个七核锰配合物{K[MnⅡMnⅢ6(teaH)3(tea)3(NCS)6]}n(1)(teaH3=三乙醇胺),通过元素分析和红外光谱对其进行了表征,并通过X-单晶衍射确定了其晶体结构。1的阴离子由外围6个锰髥与1个中心Mn髤通过6个μ3-O键连接成1个类似车轮的环状结构。直流磁化率研究结果表明,该配合物具有较高的自旋基态(S=29/2),其磁性行为说明在高自旋的Mn髤和Mn髥之间存在铁磁性相互作用。     

一种混合价态钌配合物的合成、晶体结构和电化学性质

[Ru6(μ-O2CCH3)12(CH3OH)2(HCOO)2][Ru2(μ-O2CCH3)4(H2O)2](PF6)2.2H2O(Ru2(Ⅱ,Ⅲ)混合价)是通过二步反应合成的。首先Ru2(O2CCH3)4Cl在加热条件下与甲醇反应得到红棕色中间物,然后将该中间物在甲醇水(体积比7∶1)溶液中用Ag2SO4和NH4PF6进行脱氯配位反应得到此化合物。用元素分析、红外光谱、热重分析、循环伏安、X-衍射单晶结构分析等对其进行了表征。晶体结构表明,标题化合物的晶体属单斜晶系,空间群为P21/n,晶胞参数:a=0.85362(14)nm,b=1.19589(19)nm,c=3.6642(6)nm,β=92.316(3)°,Z=2,每个结构基元包含2个不同的配离子,其中[Ru2(μ-O2CCH3)4(H2O)2]+是1个双核钌配离子,[Ru6(μ-O2CCH3)12(CH3OH)2(HCOO)2]+是由另1个由甲醇配位、甲酸根桥连的六核钌配离子。2个独立的结构单元通过氢键形成三维超分子网络结构。采用循环伏安法对其电化学性质进行了表征,结果为一对准可逆的氧化还原峰,表明该配合物的中心金属二价钌原子Ru(Ⅱ)与三价钌原子Ru(Ⅲ)之间存在电子转移。     

两个由4-酰基吡唑啉酮衍生物构筑的Mn(Ⅱ)配合物的合成、晶体结构及性质(英文)

以4-酰基吡唑啉酮衍生物为配体合成了2个Mn(Ⅱ)配合物[Mn2L2(μ-CH3OH)2(CH3OH)2](1)和{[Mn L(μ-CH3OH)]·CH3OH·CHCl3}n(2)(H2L=N-(1-苯基-3-苄基-4-丙烯基-5-吡唑啉酮)-异烟酰肼),利用元素分析、红外光谱、紫外光谱、热重和X-射线单晶衍射分析进行了表征。结果表明反应体系的p H值影响配体的配位方式,所得配合物1为双核结构,而2为2D网状结构。热重分析表明,配合物1的稳定性高于配合物2的。     

2-吡啶甲醇和1,1,1-三羟甲基乙烷混合配体七核锰配合物的合成、晶体结构与磁性（英文）

四水合氯化锰、2-吡啶甲醇和1,1,1-三羟甲基乙烷在乙腈里反应合成出一个七核Mn簇合物[Mn~Ⅱ_3Mn~Ⅲ_4(Cl)_6(hmp)_6(thme)_2]·H_2O·3CH_3CN(1·H_2O·3CH_3CN,hmpH为2-吡啶甲醇,thme H_3为三羟甲基乙烷),并对该化合物进行X射线衍射单晶结构分析、元素分析、红外光谱和磁性研究。1·H_2O·3CH_3CN属于单斜晶系I2/a空间群,配合物核骨架可看成由交替的MnⅡ和MnⅢ离子形成一个六边形,而这个六边形又围绕在1个MnⅢ离子的周围,这种结构类型的配合物以前并没有报道过。磁性研究表明,化合物1·H_2O中MnⅢ与MnⅡ或MnⅢ与MnⅢ离子之间总体是铁磁性耦合的,交流磁化率研究发现该化合物有弱的频率依赖现象。     

类Salen和β-二酮稀土配合物的晶体结构和荧光性质（英文）

通过1,3-苯二胺缩邻香兰素和Ln(acac)3·H2O(Ln=Ce,Eu)反应,合成了2种双核稀土配合物[Ce2L(acac)4(CH3OH)]2·2CH2Cl2(1)和[Eu2L(acac)4(CH3OH)]2·2CH2Cl2(2)。X射线单晶衍射分析确定了配合物的晶体结构,配合物中2个稀土离子均为8配位,具有相同的反四棱柱的配位构型。荧光性质研究表明配合物2显示稀土离子和配体共发光,主要原因是配体1,3-苯二胺缩邻香兰素的三线态能级与中心离子Eu(Ⅲ)的三线态能级相匹配。     

基于对叔丁基杯[8]芳烃的3d-5f核簇化合物(M_xTh_y,M=Co、Ni、Zn)的合成、结构与磁性研究(英文)

本文以对叔丁基杯[8]芳烃(H8C8A)为配体,在溶剂热条件下制得了3个3d-5f化合物,[Co2Th4(HC8A)2O2(OH)2(DMF)6](1)、[Ni2Th5(H2C8A)(C8A)O4(OH)2(DMF)5(CH3OH)2](2)、[Zn2Th6(HC8A)(C8A)O5(CH3O)(C3H6NO2)2(DMF)5(CH3OH)](3)(其中H8C8A=对叔丁基杯[8]芳烃,DMF=N,N-二甲基甲酰胺)。X-射线单晶测试表明,这3个化合物均为2个以尾对尾方式排列的杯[8]芳烃分子中间夹1个3d-5f核簇的三明治型结构。杯[8]芳烃均表现为双锥式构型,且每个锥式空腔下缘结合1个钍离子,双锥的连接处及2个杯芳烃分子之间由过渡金属离子或钍离子连接。不同过渡金属离子不同的配位环境导致3种不同核簇的形成。化合物1的磁性研究表明,该化合物在低温下表现出弱铁磁性相互作用。     

离子型有机锡化合物的合成及其生物活性

利用有机锡卤化物与有机酸在有机胺存在下反应合成了一系列离子型有机锡化合物,分子通式为[HNR3][(PhCH2)3Sn(μ2-SCH2COO)Cl]、[HNR3][Ph3Sn)3(O2CCH2CO2)2]·CH3CH2OH和[HNR3] [MeCy2ClSnO2CCH2CO2SnClCy2Me]。化合物的体外抗肿瘤、杀菌和杀螨活性测试结果表明,部分化合物具有很好的生物活性。[HNR3][(Ph3Sn)3(O2CCH2CO2)2]·CH3CH2OH和[HNR3] [MeCy2ClSnO2CCH2CO2SnClCy2Me]配合物对人肺癌细胞株A-549、结肠癌细胞株HCT-8和肝癌细胞株Bel-7402的抑制率约为90%,[HNR3][MeCy2ClSnO2CCH2CO2SnClCy2Me]配合物对小麦赤霉、番茄早疫、芦笋茎枯、苹果轮纹、花生褐斑的杀死率都为100%,配合物[HNR3] [MeCy2ClSnO2CCH2CO2SnClCy2Me]的杀螨活性致死率大于90%。     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.